'I appreciate that. Soon as I've something concrete, I'll call you. Josh, thanks for introducing us. It's the first time I've met someone you actually shut up for,' I said.

'You don't deserve me, Kate,' he said sadly.

Thank God for that. Now, if you'll both excuse me, I've got to run,' I said. I stood up and shook Delia Prentice's hand. 'I'll be in touch. Oh, and Josh? Thank Julia for that information she dug out for me.' I gave him a peck on the cheek.

My guilty conscience over talking to DO Delia Prentice about Ted's problem gave me a severe prick when I walked into the office to find the conservatory builder and the lovestruck secretary with their heads together. Ted Barlow was perched on the edge of Shelley's desk, while she ignored her computer screen and stared instead into his eyes. Before I'd even got my duffel coat off, Ted was apologizing for bothering me and Shelley was twittering about interim reports and mobile phones. I invited Ted into my office and brought him as up to date as I dared. I didn't trust him entirely with full knowledge of my current surveillance. He may have been footing the bill, but he was far too transparent for me to feel comfortable with him knowing my every move. Besides, he was so obviously one of life's honest guys that he might be uncomfortable at the thought of me bending the law on his behalf.

So I told him that I was making progress, and that I was close to working out how it all came together. He seemed satisfied with that. Maybe all he was looking for was some reassurance. When I emerged from my office a couple of minutes after he'd left me, he was still hanging round Shelley's desk looking nervous. I couldn't stand it, so I grabbed my coat and the mobile phone that had arrived that morning and headed for the door.

First stop was the hired Fiesta with the receiving equipment. At first, when I checked the cassettes, my heart sank. Nothing seemed to have been recorded at all since I'd left it the previous evening. When I reset it, I must have made a mistake, I decided. Then I noticed that the first tape wasn't quite empty.

I pulled it out of the machine and smacked it in the car cassette. There was the unmistakable sound of a door slamming, then a phone ringing, unanswered. I breathed a sigh of relief. Neither I nor the machine was faulty. It seemed the woman just hadn't come home. In case she or one of her neighbours was the noticing kind, I drove the Fiesta round the block and reparked it in an obviously different position. I didn't want to be in the embarrassing position of having the bomb squad called because some civic-minded nosy-parker thought the receiver on the parcel shelf was an IRA car bomb. It happened to Bill last year. Luckily for him, the receiver was switched off at the time. Luckily, because the offence is using the equipment, not possessing it, which is the kind of logic the law specializes in.

I reckoned it still wasn't safe to go back to the office, so I decided to poke a stick into the hornets nest of Alexis's little problem and see what flew out. It was late morning when I reached Cheetham's office. His obliging secretary told me he was in a meeting, but if I cared to wait…

I took the computer magazine I usually carry out of my handbag and settled down with an article about ram expansion kits. If I decided we needed something similar, the technique is to leave the magazine lying around the office, open at the appropriate page, and wait for Mortensen the gadget king to fall upon it and embrace it as if it were his own idea. Never fails.

Before I could reach a firm decision, the door to the inner office opened and Cheetham ushered out the woman I'd seen with him in Buxton. He had his arm round her in that familiar, casual way that people use with the kind of partners you sleep with rather than work with. When he saw me, he twitched and dropped his arm as if he'd been jabbed with a cattle prod. 'Miss Brannigan,' he said nervously.

Hearing my name, the woman, who until then had been focused on Cheetham, switched her attention to me. She sized me up in an instant, from the top of my wavy auburn hair to the tips of my brown boots. She probably misjudged me, too. She wasn't to know that the reason I was wearing enough make-up to read the six o'clock news was that the bruises on my jaw and cheekbone had gone a fascinating shade of green.

She looked like serious business, groomed to within an inch of artificiality. I hated her. Our mutual scrutiny was interrupted by Cheetham stammering, 'If you'd like to come through, Miss Brannigan?'

I acknowledged them both with a nod and walked past them to his office. I didn't hear what the woman murmured in his ear after I passed, but I heard him say, 'It's all right, Nell. Look, I'll see you this afternoon, OK?'

'It had better be,' I thought I caught as she swept off without so much as a smile for the secretary. You can tell a lot about people by the way they treat other people's office staff.

I waited for Cheetham to return to his chair. I could see the effort it was taking for him to sit still. 'How can I help you?' he asked.

'I just thought I'd drop by and give you a progress report,' I said. 'Our builder friend, T.R. Harris, seems not to exist. And neither does the solicitor whom you appear to have corresponded with.' I knew this for certain, since I'd checked out the list of qualified briefs in the Solicitors' Diary.

Cheetham just sat and stared at me, those liquid dark eyes slightly narrowed. 'I don't understand,' he said, rather too late.

'Well, it seems as if Harris used a false name, and made up a non-existent solicitor for the purpose of conning your clients out of their money. It was lucky that Miss Appleby happened to discover the land had already been sold, otherwise they'd all have lost a lot more money,' I tried. If he was straight, he'd be at great pains to point out to me that they couldn't have lost another shilling, since he, their diligent solicitor, would have discovered from the Land Registry that the land in question had already been sold, or was at least the subject of other inquiries.

He said none of that. What he did say was how sorry he was that it had happened, but now I seemed to have cleared it all up, it was obvious that he had been taken for a ride as much as his clients.

'Except that, unlike you, they're all out of pocket to the tune of five thousand pounds each,' I observed mildly. He didn't even blush.

Cheetham got to his feet and said, 'I appreciate you letting me know all this,' he said.

They might even have to take the matter to the Law Society. They have indemnity insurance to cover this sort of negligence and malpractice, don't they?'

'But I haven't been negligent,' he protested weakly. 'I told you before, the searches came back clear. And the letters from Harris's solicitor assured me that although he'd had other inquiries, no one else was in a position to pursue a possible purchase at that point in time. How was I to know the letters were fakes?'

'It's a pity you solicitors always have to put everything in writing,' I said. 'Just one phone call to the so-called Mr. Graves' office would have stopped this business stone dead.'

'What do you mean?' he asked hesitantly.

The number on the letterhead is the number of a pay phone in a pub in Ramsbottom. But I suppose you didn't know that either,' I said.

He sat down again in a hurry. 'Of course I didn't,' he said. He was as convincing as a cabinet minister.

There was one other thing,' I said. I'd rattled his cage. Now it was time for a bluff. 'When I was here the other day, I saw a guy come into your office after me. I had some other business in the building, and when I left, I saw him getting into his van. Some company called Renovations, or something like that? Looked a bit like your friend from Buxton, which, of course, is why I thought he was a builder.'